GC Troubleshooting—No Injection Instrument Blanks

Description

Effective gas chromatography troubleshooting requires a lot of knowledge and skill. There are also some key techniques that a troubleshooter will use time and again to help track down and isolate a problem. The “no injection instrument blank” is one of the techniques that we can use to help learn more about a problem that we might be experiencing. It can help us to learn whether a problem is within the instrument itself, or is introduced as part of our sample injection. 

Additional Resources

• No Injection Instrument Blank Blog

Restek Recommended Tools & Parts

• Viton O-Rings
• GC Syringes

Transcript

Thanks for joining us for this Restek Tip where we will talk about no injection instrument blanks, which are a really useful tool for scouting out where contamination that you're observing in your data might be coming from. So, let's say you've got some unwanted peaks. Now, they're peaks. They're sharp. They look like the other chromatographic peaks. They aren't blobs. So you know this extraneous material is coming from before the column because it's passing through the chromatographic system and being chromatographed. That's why we see them as peaks. But, where? Could it be coming from inside of your inlet or somewhere farther up the gas stream in your instrument? Or is it coming from outside of your instrument?  

Say you have a dirty rinse vial or syringe or maybe even your sample itself. Well, one easy way to at least divide inside from outside of the instrument is to perform a no injection instrument blank, which is exactly how it sounds. You run your analysis without making an injection. And if you do that and still see the peaks present, well then that's your sure fire sign that you have contamination originated from somewhere inside the instrument. Maybe it's an O-ring or a piece of cored septa that's landed in your liner. But if those peaks go away, during a no injection instrument blank, now you know to focus your attention outside of the instrument. So no injection instrument blanks really help you focus your troubleshooting, save some time, and I have found them to be particularly helpful. So, thank you for joining us for this Restek Tip and good luck.